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问题:

I am trying to connect devices through my app installed in Nexus 5.I want to make an app like rainbow contacts in android. In my app I aim to connect to another device through Bluetooth and transfer set of contacts or files. I followed this question, but the workaround mentioned there is not working for me Here is my full code. This is the code snippet from my application where I have tried to get the socket and make connections.

I am able to get through pairing device dialog ,but when i trying to paired then error is raised

//to create socket if (secure) {             bluetoothSocket = device.createRfcommSocketToServiceRecord(uuid);         } else {             bluetoothSocket = device.createInsecureRfcommSocketToServiceRecord(uuid);         } //connection establishment try {                  bluetoothSocket.connect();                 success = true;                 break;             } catch (IOException e) {                 //try the fallback                 try {                     Class<?> clazz = tmp.getRemoteDevice().getClass();                     Class<?>[] paramTypes = new Class<?>[] {Integer.TYPE};                     Method m = clazz.getMethod("createRfcommSocket", paramTypes);                     Object[] params = new Object[] {Integer.valueOf(1)};                     bluetoothSocket  = (BluetoothSocket) m.invoke(tmp.getRemoteDevice(), params);                     Thread.sleep(500);                     bluetoothSocket.connect();                     success = true;                     break;                 } catch (FallbackException e1) {                     Log.w("BT", "Could not initialize FallbackBluetoothSocket classes.", e);                 } catch (InterruptedException e1) {                     Log.w("BT", e1.getMessage(), e1);                 } catch (IOException e1) {                     Log.w("BT", "Fallback failed. Cancelling.", e1);                 }             }

Error I am getting

09-06 13:44:57.247  27860-27860/com.example.gauravdubey.myapplication I/BT： Attempting to connect to Protocol: 00001101-0000-1000-8000-00805f9b34fb 09-06 13:44:57.247  27860-27860/com.example.gauravdubey.myapplication W/BluetoothAdapter： getBluetoothService() called with no BluetoothManagerCallback 09-06 13:44:57.247  27860-27860/com.example.gauravdubey.myapplication D/BluetoothSocket： connect(), SocketState: INIT, mPfd: {ParcelFileDescriptor: FileDescriptor[56]} 09-06 13:44:58.667  27860-27860/com.example.gauravdubey.myapplication W/BluetoothAdapter： getBluetoothService() called with no BluetoothManagerCallback 09-06 13:44:58.667  27860-27860/com.example.gauravdubey.myapplication D/BluetoothSocket： connect(), SocketState: INIT, mPfd: {ParcelFileDescriptor: FileDescriptor[59]} 09-06 13:45:03.267  27860-27860/com.example.gauravdubey.myapplication W/BT： Fallback failed. Cancelling.     java.io.IOException: read failed, socket might closed or timeout, read ret: -1             at android.bluetooth.BluetoothSocket.readAll(BluetoothSocket.java:505)             at android.bluetooth.BluetoothSocket.waitSocketSignal(BluetoothSocket.java:482)             at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:324)             at com.example.gauravdubey.myapplication.BluetoothConnector$FallbackBluetoothSocket.connect(BluetoothConnector.java:198)             at com.example.gauravdubey.myapplication.BluetoothConnector.connect(BluetoothConnector.java:62)             at com.example.gauravdubey.myapplication.ConnectThread.run(ConnectThread.java:101)             at com.example.gauravdubey.myapplication.MainActivity$1.onItemClick(MainActivity.java:288)             at android.widget.AdapterView.performItemClick(AdapterView.java:299)             at android.widget.AbsListView.performItemClick(AbsListView.java:1113)             at android.widget.AbsListView$PerformClick.run(AbsListView.java:2911)             at android.widget.AbsListView$3.run(AbsListView.java:3645)             at android.os.Handler.handleCallback(Handler.java:733)             at android.os.Handler.dispatchMessage(Handler.java:95)             at android.os.Looper.loop(Looper.java:136)             at android.app.ActivityThread.main(ActivityThread.java:5001)             at java.lang.reflect.Method.invokeNative(Native Method)             at java.lang.reflect.Method.invoke(Method.java:515)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)             at dalvik.system.NativeStart.main(Native Method) 09-06 13:45:03.267  27860-27860/com.example.gauravdubey.myapplication V/connectThread： Could not connect to device: B0:D0:9C:8B:A4:47 09-06 13:45:03.267  27860-27860/com.example.gauravdubey.myapplication I/Choreographer： Skipped 361 frames!  The application may be doing too much work on its main thread.

So what i am doing wrong ? any help would be appreciated

回答1:

In the constructor of BluetoothConnector.java, a list of uuidCandidates is passed.

public BluetoothConnector(BluetoothDevice device, boolean secure, BluetoothAdapter adapter,                               List<UUID> uuidCandidates)            {         this.device = device;         this.secure = secure;         this.adapter = adapter;         this.uuidCandidates = uuidCandidates;          if (this.uuidCandidates == null || this.uuidCandidates.isEmpty()) {             this.uuidCandidates = new ArrayList<UUID>();             this.uuidCandidates.add(UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66"));         }     }

Have you passed it null?

If yes,then try calling device.fetchUuidsWithSdp() for the Bluetooth device you want to connect and receive BluetoothDevice.ACTION_UUID intent in your receiver.As this will fetch a list of uuids supported for the device.

回答2:

Within the try ("//try the fallback") use this:

socket =(BluetoothSocket) device.getClass().getMethod("createRfcommSocket", new Class[] {int.class}).invoke(device,1); socket.connect();

Another tip may be to use a different UUID, it may solve the problem.

I don't know if you tryed it yet, but similarly to what has been done in the bluetooth chat example, just before creating your ConnectThread, call this function:

public synchronized void connect(BluetoothDevice device) {      // Cancel any thread attempting to make a connection     if (mState == STATE_CONNECTING) {         if (mConnectThread != null) {             mConnectThread.cancel();             mConnectThread = null;         }     }      // Cancel any thread currently running a connection     if (mConnectedThread != null) {         mConnectedThread.cancel();         mConnectedThread = null;     }      // Start the thread to connect with the given device     mConnectThread = new ConnectThread(device);     mConnectThread.start();     setState(STATE_CONNECTING); }

回答3:

I have this strangest thing on the Android 5.0 system you might have to clear cache as suggested here: http://www.gottabemobile.com/2014/12/01/nexus-lollipop-problems-fixes/

and also you might need to disconnect the bt dongle so it won't occupy the previous connection in memory if you use a pc and a cheap bt dongle transmitter

回答4:

Dirty cache. Find where on the device to clear app cache, then reboot the thing. You may have a device flow control interrupter (firewall, app wall, security software) that intercepts the port and re-issues it-- this is the problem. Depending upon where it instantiates at startup, it's now different than what your app wants. Therefore, rebuild the table by snarfing the cache and rebooting to build the cache/redirect tables back. I know this sounds wickedly ephemeral, but it worked for me.

文章来源: Bluetooth Connection failed “java.io.IOException: read failed, socket might closed or timeout, read ret: -1”

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